LD-84-051, Discusses Potential Single Failure of Sys 80 Auxiliary Pressurizer Spray Sys.Potential Failure Involves Possibility of Valve CH-240 Sticking in Full Open Position.Info Closes Out CESSAR Confirmatory Issues 1 & 2,per NUREG-0852

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Discusses Potential Single Failure of Sys 80 Auxiliary Pressurizer Spray Sys.Potential Failure Involves Possibility of Valve CH-240 Sticking in Full Open Position.Info Closes Out CESSAR Confirmatory Issues 1 & 2,per NUREG-0852
ML20097J449
Person / Time
Site: 05000470
Issue date: 09/18/1984
From: Scherer A
ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY
To: Eisenhut D
Office of Nuclear Reactor Regulation
References
RTR-NUREG-0852, RTR-NUREG-852 LD-84-051, LD-84-51, NUDOCS 8409210251
Download: ML20097J449 (1)


Text

7 C-E Power Systems Tel. 203/688-1911 Combustion Engineering Inc. Telex: 99297 1000 Prospect Hill Road Windsor, Connecticut 06095 POWER M SYSTEMS STN 50-470F Septemoer 18, 1984 LD-84-051 Mr. Darrell G. Eisenhut, Director Division of Licensing ,

U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

CESSAR Confirmatory Issues 1 and 2

Reference:

NRC Letter, C. O. Thomas to A. E. Scherer, dated March 27, 1984

Dear Mr. Eisenhut:

The Reference identified what the Staff considers to be vulnerability for a potential single failure of the System 80" auxiliary pressurizer spray system.

This potential single failure centered on the possibility of valve CH-240 sticking in the full open position, thus substantially reducing the auxiliary spray system flow and, consequently, the plant depressurization rate.

To resolve this concern, C-E will add an additional valve to this portion of the Chemical and Volume Control System (CVCS) described in CESSAR. The additional valve will be positioned in series with CH-240. The valve will be procured to the same quality and seismic standards as CH-240, ar.d will either be a fail-closed valve or it will be powered from an emergency power supply.

Figure 9.3-4 (P&ID for the CVCS) will be modified to show addition of the valve in a later amendment to CESSAR-F.

We understand that this change closes out Confirmatory Issues 1 (Shutdown Cooling Analysis) and 2 (Steam Generator Tube Rupture) as identified in su,nplement No. 2 to the CESSAR Safety Evaluation Report (NUREG-0852). If you have any additional questions or comments on this issue, please feel free to call me or Mr. T. J. Collier of my staff at (203) 285-5215.

Very truly yours, COMBUSTION ENGINEERING, INC.

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840921g2{0 0 A.E.dh'erer PDR AD C PDR Director P Nuclear Licensing AES:las cc: K. Eccleston (USNRC Project Manager) p(p) 1 0